Method of treating refractory electric-furnace products.



STATES rn ENT OFFICE..-

EOEE N. JEPrsoN, or WORCESTER, MASSACHUSETTS, ASSIGNOR.'1O NORTON com- PANY, oE-woncEs EE, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS. I

METHOD OF TREATING. REFRACTORYELECTRIC-FURNACE rEonUcTs.

Specification of Letters Patent.

Patented May 23, 1911.

tho-Drawing. Application filed August 21,1909. Serial No. 14,019..

To all 1127mm it may concern:

{Be it. known that I, GEORGE N. Jameson, a citizen of-the United States, residing at Worcester, in the county of Worcester and State of Massachusetts, have invented certain; new and useful Improvements in Methods of Treating Refractory Electric- Furnace Products, of which the following is ,a' Specification.

The object'of this invention is the pro ision of a method whereby certain highly refracto electric furnace products, and specifical y silicid of carbon or. carborundum, may-be improved and rendered better terials 'vorpimpleinents, and for other puradapted for the preparation of abrasive maposes. v

As is well known, silicid of carbon is prepared by the reduction in the electric furnace of sand-by means of coke or ot'h'er form f of carbon. In this operation there occurs a simultaneous reduction of the impurities of v the sandand coke, as for example oxids -of iron, calcium, etc, with the formation of carbids, silicids or other reduction products.

' The separation of these in the washing procish ed article or implement is highly objecf'esses to which, the crushed electric furnace is afterw'ar roduct of the submitted is incomplete, and their presence in the' fintionable and prejudicial. I have found however that the impurities exist chiefly in the "formof a superficial coating on the grains, c stals or crystalline fragments of the siliold of carbon, being apparently excluded '{from the body of the grains by the phenomena attending crystallization; and

that by suitably treating the crushed grains [the impurities may be brought into such condition that they are capable of removal by a' mulling or grinding operation. Ac-

": i5 crushed, and preferably but not necessarily v cording to the present invention such impurities existing in the product as prepared 1n the electric furnace are first reoxidized by subjecting the material, previously reduced to such size or sizes as are suited for use, to an oxidizing roast under such conditions of time and temperature as fully .to oxidize the impurities without injurious efiect upon the silicid carbon: The fully'l oxidized material is then subjected to a mulling, tumbling "or similar operation with the result that the oxidized impurities, such as silica, silicate of iron, .etc., which are present chiefly as a coating upon the grains or adhere thereto, are detached by the. abrading action of the grains. This operation also has the effect of shaping the grains and breaking down aggregates into their constituent grains. The mulled product,

after washing, is found to consist essentially I of the abraslve grains, freed from all a herentor admixed materials which might injuriously affect either the efficiency or the durability of the grains or of implements or articles prepared from them. The grains may then be graded and subjected to such further treatment as may be required by the intended use. a

I claim -1. The method of purifying sllicid of car'- I bon, which consists in roasting the material, suitably subdivided, under oxidizing conditions.

2. The method of purifying silicid of carbon, which consists in roasting the material,

suitably subdivided, under oxidizing condi- 4 tions, and separatin ties from the purifiec grains.

' 3. The method'of purifying silicid of carbon, which consists in roasting the material, suitably subdivided, under oxidizing conditions, and mulling the grains to separate therefrom the oxidized impurities.

the oxidized impuri In testimon whereof, I afiix my signature I in presence 0 two witnesses.

GEORGE N. JEPPSON.

- Witnesses: ALDUS\C, Blooms,

ROBT. P. CAPBON. 

